The present invention relates to a method for reeling a web of material, especially a paper web, onto a core, for example a spiral core, by glueing the leading end of the web of material to the core and by rotating the core until the roll is of the desired thickness, by cutting off the web of material, and by attaching the trailing end of the cut-off web to the roll. The invention relates in particular to the reeling, onto a core, of a web of material coming from unreeling frames, slitting machines or sheet cutters. In addition, the invention relates to an apparatus for carrying out the method according to the invention. At the same time the invention relates to a roll of a web of material, which is surrounded by a wrapping protecting and supporting the roll, and to a method for forming such a wrapping during the reeling.
It is previously known to reel a paper web coming from a slitting machine or a sheet cutter onto a core by attaching the leading end of the web to the core manually by using various means such as masking tape, staples and the like. The trailing end of the paper web has also been attached to the roll manually using masking tape or by applying glue to the trailing end of the web by means of a brush.
The length of the web of material reeled onto a core, and thereby also the thickness of the completed roll, varies, and therefore the core is subjected to strains of varying intensity during the reeling and during the further handling subsequent to the reeling, such as moving of the rolls and unreeling. Thus, cores of different thicknesses and different strengths are required for these different needs. In addition, it has been observed that especially the ends of the cores are subjected to greater than normal strains during the transportation or handling of the rolls, and for this reason it is common to fit a peg at one or both ends of the hollow in the core. Alternatively, the ends of the cores are provided with sleeves in order to reinforce the cores.
The object of the present invention is to eliminate these disadvantages and to provide a method and apparatus for reeling a web of material onto a core, which does not require any pegs or sleeves for reinforcing the ends of the core nor cores of different strength, depending on the reeling speed, the roll thickness or the further handling of the roll. The object of the present invention is thus to provide a method for reeling webs of material of different lengths at different speeds onto cores of one and the same size by glueing the leading end of the web of material to the core and by rotating the core until the roll is of the desired thickness, by cutting off the web of material, and by attaching the trailing end of the cut-off web of material to the roll. The object of the invention is, furthermore, to provide a roll of a web of material surrounded by a wrapping which protects and supports the roll as well as a method for attaching the trailing end of the cut-off web of material to the roll, the method enabling a very strong wrapping, which protects and supports the roll, to be produced.
The object of the invention is finally to provide reeling apparatus intended to be installed at a point subsequent to a slitting machine or a sheet cutter or an unreeling device.
It is previously known to form the core so as to form one unit with the web of material which is reeled onto it. In this case, several rounds of the web of material are reeled onto the reeling spindle, the rounds being at the same time glued to each other to produce a core, whereafter the reeling is continued directly without glueing. However, this method of reeling requires the use of a special reeling spindle, and it cannot be applied to spindle-less reeling, which is currently favored. Furthermore, the reeling spindle must be an expansion shaft, because otherwise it would not be possible to remove it from the center of the roll. Finally it should be noted that in slitting machines it is not possible to use this prior known method of reeling, since a slitting machine does not have spindles.
According to the invention there is now provided a method which starts from a relatively weak core base which is of low quality and therefore inexpensive, and then so many layers of the web of material are glued onto it that the thickness of the thus created core, and thereby its strength, is sufficient for reeling and the further handling of the roll.
Within the same inventional idea it is possible to attach the trailing end of a cut-off web of material to the roll by starting the applying of the glue in good time before the cutting off of the web of material so that there is formed around the roll a wrapping consisting of several layers glued to each other, protecting and supporting the roll.
It has been surprisingly observed that a glued core prepared by the method according to the invention is far more durable than a spiral core of the same thickness and size. Furthermore, the surface of a glued core prepared according to the invention is much smoother, and therefore it is possible to use the leading end of the paper web much more efficiently, i.e. less reject produced during unreeling. Effective glueing of the trailing end of the paper web to the roll also reduces reject during the transportation and further handling of the roll. This means improved safety at work, since the floors keep clean.
The glueing members used in the method and apparatus according to the invention can also be used for glueing together the ends of the parts of a web which has broken off, for joining several paper webs to each other by the ends, and for glueing several layers of paper to form multiple-layer paper using a paper of inferior quality in the intermediate layers. In addition, it is possible to connect to the glue-applying members moistening members for adjusting the moisture content of the paper web in its transversal profile, members for applying various additives to the surface of the paper web, and members for marking the paper web, for example for marking the paper web at some distance from its leading end so that at the unreeling stage it is known in advance how long unreeling can be continued before the paper web ends. All these are additional advantages, which also have great economical significance.
The primary advantage of the present invention is, however, the fact that one single core type can be used for all reeling purposes in practice, without having to lower the standards for the strength of the core and without having to use expensive and awkward pegs or sleeves at the ends or the core.